How Can I Calculate the Adjustment Amount on Form Keogh, Sep, and Simple Contribution Worksheet for Notary

Hi there, I've already gone through the Self-Employment Screen in the Business Section and indicated that I am a Notary there so we're good on Sch C, and TT told me that I owe no SE Tax because I put in my Net Income, but for the purposes of calculating the maximum amount allowed to put in my 401(k), I have to make an adjustment.  I remember last year that someone walked me through it.  The number belongs on Part II, 1b and 1c.  On line 2a, it is listing a deductible portion of self-employment tax, which I guess is the part that has to be adjusted since I have no self-employment tax.  I did this last year but can't remember how I did it.  Any help is appreciated.